The LTE-A (Long Term Evolution-Advanced) is a further evolved and enhanced system based on a 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) system. In the LTE-A system, a CA (Carrier Aggregation) technology is introduced, which is also referred to as a frequency spectrum aggregation technology or bandwidth expansion technology. In a carrier aggregation scenario, frequency spectrums of two or more CCs (Component Carriers) are aggregated to obtain larger transmission bandwidth.
When performing decoding, an eNB (Evolved NodeB, base station) needs to learn the total number of bits of the original information of UCI (Uplink Control Information) joint channel coding adopted by a UE, that is, to ensure that the eNB and UE have consistent understanding on the total number of bits of the original information of UCI joint coding of multiple downlink carriers, so as to perform correct decoding. However, the existing method for transmitting UCI causes the eNB to decode the jointly coded UCI incorrectly.